• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.3
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• pp.287-292
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• 2012

The results of this study intended to clarify the apoptotic effects of curcumin on Epstein-Barr virus transformed human B lymphoma (EBV-B) cells are summarized as follows: It was found that curcumin induced endoplasmic reticulum(ER) stress as well as apoptotic cell death in EBV-B cells, although the magnitude of action was insignificant. When EBV-B cells activated by pokeweed mitogen (PWM) were treated with the same concentrations of curcumin, it was found that higher ER stress (GRP78, P-PERK, XBP-1, ATF6, and CHOP expressed) increased unfold protein response (UPR) and thus, apoptosis attributed to ER stress, compared to non-activated EBV-B cells In conclusion, it is expected that curcumin will play an important role for leukemia treatment.

• BMB Reports
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• v.34 no.5
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• pp.457-462
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• 2001

Using the monomolecular film technique, we compared the interfacial properties of Staphylococcus simulans lipase (SSL) and Staphylococcus aureus lipase (SAL). These two enzymes act specifically on glycerides without any detectable phospholipase activity when using various phospholipids. Our results show that the maximum rate of racemic dicaprin (rac-dicaprin) hydrolysis was displayed at pH 8.5, or 6.5 with Staphylococcus simulans lipase or Staphylococcus aureus lipase, respectively The two enzymes interact strongly with egg-phosphatidyl choline (egg-PC) monomolecular films, evidenced by a critical surface pressure value of around $23\;mN{\cdot}m^{-1}$. In contrast to pancreatic lipases, $\beta$-lactoglobulin, a tensioactive protein, failed to inhibit Staphylococcus simulans lipase and Staphylococcus aureus lipase. A kinetic study on the surface pressure dependency, stereoselectivity, and regioselectivity of Staphylococcus simulans lipase and Staphylococcus aureus lipase was performed using optically pure stereoisomers of diglycerides (1,2-sn-dicaprin and 2,3-sn-dicaprin) and a prochiral isomer (1,3-sn-dicaprin) that were spread as monomolecular films at the air-water interface. Both staphylococcal lipases acted preferentially on distal carboxylic ester groups of the diglyceride isomer (1,3-sn-dicaprin). Furthermore, Staphylococcus simulans lipase was found to be markedly stereoselective for the sn-3 position of the 2,3-sn-dicaprin isomer.

• BMB Reports
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• v.44 no.11
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• pp.735-740
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• 2011

Tunicamycin, an endoplasmic reticulum (ER) stress inducer, specifically inhibits N-glycosylation. The cyclic AMP (cAMP) response element-binding protein H (CREBH) was previously shown to be regulated by UPR-dependent proteolytic cleavage in the liver. On the other hand, the role of CREBH in other tissues is unknown. In the present study, tunicamycin increased the level of CREBH activation (cleavage) as well as mRNA expression in osteoblast cells. Adenoviral (Ad) overexpression of CREBH suppressed BMP2-induced expression of alkaline phosphatase (ALP) and osteocalcin (OC). Interestingly, the BMP2-induced OASIS (structurally similar to CREBH, a positive regulator of osteoblast differentiation) expression was also inhibited by CREBH overexpression. In addition, inhibition of CREBH expression using siRNA reversed the tunicamycin-suppressed ALP and OC expression. These results suggest that CREBH inhibited osteoblast differentiation via suppressing BMP2-induced ALP, OC and OASIS expression in mouse calvarial derived osteoblasts.

• Design & Manufacturing
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• v.13 no.4
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• pp.51-56
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• 2019

Due to industrial development, the importance of GD&T tolerance is growing day by day. Roundness measurement means the size deviated from the ideal circle. Roundness evaluation methods include LSCI, MZCI, MCCI, and MICI. Generally, A is used a lot at industrial evaluation. In this experiment, we studied the variations in table velocity, filter values, and detector angles, which can cause errors in roundness measurements. The measurement conditions were table speeds of 10, 30 and 60 mm/s, probe angles of 10, 20 and 30 degrees and frequency filter settings of 15, 150 and 500 upr and The number of experiments was measured 30 and the average value was chosen as a representative value. The hypothesis test showed that the p-value for the frequency filter was greater than 0.05, and the experiment rejected the null hypothesis and adopted the alternative hypothesis.

• YAKHAK HOEJI
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• v.41 no.5
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• pp.559-564
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• 1997

To find out antitumor active principles from natural resources, we have evaluated various extracts from the leaves of Alnus hirsuta (Betulaceae). The ethylacetate extract of this plant was found to show a significant cytotoxicity against several kinds of cultured human solid tumor cell lines (AGS, A5 49, HCT15, SKOV3, HEP3B) in vitro. Using cytotoxicity-guided chromatographic purification of the ethylacetate extract, cytotoxic constituent:1,7-bis-(4-hydroxyphenyl)-5-(${\beta}$-D-glucopyranosyloxy)-3-heptanone, was isolated and structurally identified by physico-chemical properties and spectroscopic evidences.

• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.86-91
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• 2007

A representative group of 38 improved basmati lines including maintainers of sterile lines were studied for genetic diversity utilizing Mahalanobis $D^2$ statistics. A wide diversity was observed having ten clusters with high intra- and inter-cluster distance. Heterosis was estimated utilizing the cytoplasmic male sterile lines from the clusters having high intra- and inter-cluster distance. Highly heterotic hybrids were obtained from the hybridization programme. Cross combinations IR68281A/Pusa 1235-95-73-1-1, IR68281A/RP 3644-41-9-5, Pusa 3A/UPR 2268-4-1, IR 68281A/Pusa Basmati-1, IR68281A/BTCE 10-98, and IR58025A/HKR 97-401 were found to be highly heterotic for grain yield/plant with other agronomic and quality traits. Additionally, a positive association of intra-cluster distance with heterosis was observed, which could be utilized as a guideline for predicting heterosis in basmati hybrid rice breeding program. Also, a positive association between inter-cluster distance and heterosis was observed.

• Journal of Life Science
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• v.26 no.4
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• pp.490-495
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• 2016

Brefeldin A (BFA), a lactone antibiotic isolated from the fungus Eupenicillium brefeldianum, inhibits the transport of secreted and membrane proteins from the endoplasmic reticulum (ER) to the Golgi apparatus. BFA disrupts Golgi function, the accumulation of unfolded proteins in ER, and the induction of ER stress. Prolonged ER stress induces apoptosis at least in part through the transcription factor C/EBP (CCAAT/enhancer binding protein) homologous protein (CHOP),which is activated by the unfolded protein response (UPR). In this paper, we demonstrate that BFA-induced endoplasmic reticulum stress leads to different CHOP expression in primary astrocyte cells and C6 glioma cells. BFA induced lower CHOP expression levels in primary astrocyte cells than in C6 glioma cells; however, other ER stress inducers (thapsigargin and tunicamycin) resulted in similar expression patterns in these two cell types. Interestingly, the three different ER stress inducers (BFA, thapsigargin, and tunicamycin) induced similar levels of CHOP mRNA expression in primary astrocyte cells. The ubiquitin-proteasome inhibitor MG132 also markedly up-regulated the BFA-mediated CHOP protein expression in primary astrocyte cells. BFA also induced higher proteasome activity in primary astrocyte cells than in C6 glioma cells. Taken together, our results suggest that higher proteasomal activity might down-regulate BFA-induced CHOP expression in primary astrocyte cells.

• BMB Reports
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• v.51 no.8
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• pp.388-393
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• 2018

The activating transcription factor (ATF) 4 belongs to the ATF/CREB (cAMP Response Element Binding bZIP [Basic Leucine Zipper]) transcription factor family, and plays a central role in the UPR (Unfolded Protein Response) process in cells. The induction of ATF4 expression has previously been shown to increase the replication of HIV-1. However, the detailed mechanism underlying this effect and the factors involved in the regulation of ATF4 function are still unknown. Here, we demonstrate first that knocking out ATF4 using siRNA shows a strong negative effect on HIV-1 production, indicating that ATF4 is a functional positive cellular factor in HIV-1 production. To determine the mechanism by which ATF4 regulates the HIV-1 life cycle, we assessed the effect of the overexpression of wild type ATF4 and its various derivatives on HIV-1 LTR-mediated transcriptional activation and the production of HIV-1 particles. This effect was studied through co-transfection experiments with either reporter vectors or proviral DNA. We found that the N-terminal domains of ATF4 are involved in HIV-1 LTR-mediated transcriptional activation, and thus in HIV-1 production.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.3
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• pp.212-221
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• 2019

Sestrin-2 (SESN2) as a stress-metabolic protein is known for its anti-oxidative effects as a downstream factor of PERK pathways in mammalian cells. However, the expression patterns of SESN2 in conjunction with the UPR signaling against to ER stress on porcine oocyte maturation in vitro, have not been reported. Therefore, we confirmed the expression pattern of SESN2 protein, for which to examine the relationship between PERK signaling and SESN2 in porcine oocyte during IVM. We investigated the SESN2 expression patterns using Western blot analysis in denuded oocytes (DOs), cumulus cells (CCs), and cumulus-oocyte complexes (COCs) at 22 and 44 h of IVM. As expected, the SESN2 protein level significantly increased (p < 0.01) in porcine COCs during 44 h of IVM. We investigated the meiotic maturation after applying ER stress inhibitor in various concentration (50, 100 and 200 μM) of tauroursodeoxycholic acid (TUDCA). We confirmed significant increase (p < 0.05) of meiotic maturation rate in TUDCA 200 μM treated COCs for 44 h of IVM. Finally, we confirmed the protein level of SESN2 and meiotic maturation via regulating ER-stress by only tunicamycin (Tm), only TUDCA, and Tm + TUDCA treatment in porcine COCs. As a result, treatment of the TUDCA following Tm pre-treatment reduced SESN2 protein level in porcine COCs. In addition, SESN2 protein level significantly reduced in only TUDCA treated porcine COCs. Our results suggest that the SESN2 expression is related to the stress mediator response to ER stress through the PERK signaling pathways in porcine oocyte maturation.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.3
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• pp.211-216
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• 2014

Endoplasmic reticulum (ER) stress, unfolded protein response (UPR), and mitochondrial biogenesis were assessed following varying intensities of exercise training. The animals were randomly assigned to receive either low- (LIT, n=7) or high intensity training (HIT, n=7), or were assigned to a control group (n=7). Over 5 weeks, the animals in the LIT were exercised on a treadmill with a $10^{\circ}$ incline for 60 min at a speed of 20 m/min group, and in the HIT group at a speed of 34 m/min for 5 days a week. No statistically significant differences were found in the body weight, plasma triglyceride, and total cholesterol levels across the three groups, but fasting glucose and insulin levels were significantly lower in the exercise-trained groups. Additionally, no statistically significant differences were observed in the levels of PERK phosphorylation in skeletal muscles between the three groups. However, compared to the control and LIT groups, the level of BiP was lower in the HIT group. Compared to the control group, the levels of ATF4 in skeletal muscles and CHOP were significantly lower in the HIT group. The HIT group also showed increased PGC-$1{\alpha}$ mRNA expression in comparison with the control group. Furthermore, both of the trained groups showed higher levels of mitochondrial UCP3 than the control group. In summary, we found that a 5-week high-intensity exercise training routine resulted in increased mitochondrial biogenesis and decreased ER stress and apoptotic signaling in the skeletal muscle tissue of rats.